255987666 has 96 divisors (see below), whose sum is σ = 652017600. Its totient is φ = 71715840.

The previous prime is 255987653. The next prime is 255987671. The reversal of 255987666 is 666789552.

It is a happy number.

255987666 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 197950 + ... + 199238.

It is an arithmetic number, because the mean of its divisors is an integer number (6791850).

Almost surely, 2^255987666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 255987666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (326008800).

255987666 is an abundant number, since it is smaller than the sum of its proper divisors (396029934).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

255987666 is a wasteful number, since it uses less digits than its factorization.

255987666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1384 (or 1381 counting only the distinct ones).

The product of its digits is 5443200, while the sum is 54.

The square root of 255987666 is about 15999.6145578573. The cubic root of 255987666 is about 634.9502232253.

The spelling of 255987666 in words is "two hundred fifty-five million, nine hundred eighty-seven thousand, six hundred sixty-six".